Painting a rotated or flipped tile in a Tilemap loses collision

[warriormaster12]

Godot version

4.2 beta 2

System information

Pop Os 22.04 lts 12th Gen Intel® Core™ i7-12700H × 20 NVIDIA RTX A2000 8GB 32.0  ram. Tested on Forward+ and Mobile

Issue description

When painting a tile that is rotated or flipped, it looses its physics layer as demonstrated in this video:

2023-10-23.10-30-26.mp4

Even though in the video I showed this only happening with one of the tiles, it happens with both of them as long as you rotate or flip it.

Steps to reproduce

1. Create a tilemap and a tileset
2. Create a physics layer and set collision_visibility_mode to force show.
3. Assign just created physics layer to tiles
4. Paint the tiles and use rotate or flip tool.

Minimal reproduction project

TileTest.zip

[akien-mga]

CC @KoBeWi @groud

[KoBeWi]

Looks like editor-only bug. The tiles have correct collisions at runtime.

[warriormaster12]

Only if you load the level directly. Calling get_tree().change_scene_from_file() breaks the collision.

[warriormaster12]

Should have mentioned that

[KoBeWi]

Your minimal project is a bit incomplete; you have a script for changing scenes, but it's not attached anywhere.
Anyway, I was able to reproduce the bug.

[warriormaster12]

I originally intended to include a scene where you switch scenes because I thought that the issue was related to loading a scene. When I was able to produce the bug in the editor, I decided to delete the scene but forgot to do the same with the script.

Clearly I should have kept it and mentioned it.

[dehboxturtle]

I just saw this after I had opened a similar ticket here. #83849

Mine has a minimal project that switches scenes and shows the breakage if you want to use that. Otherwise feel free to close the duplicate.

[KoBeWi]

Removing this line fixes the issue:

godot/scene/2d/tile_map.cpp

Line 3055 in c21c270

polygon_cache.clear();

Just as I feared in #80144 (comment), clearing cache at an arbitrary point will invalidate some polygons that are still in use. As a quick-fix we could remove this line at runtime to fix scene changing bug, not sure about the editor fix.

[dehboxturtle]

MRP for anyone else who needs it
missing collisions.zip

Repro steps:

1. Start game on Scene 1
2. step on the scene switch trigger in scene 1 to go to scene 2
3. Switch back to Scene 1 from Scene 2 via the scene switch trigger and observe collision boxes missing from rotated/flipped tiles.

[groud]

Closing as fixed by #84261